A digital cinema projection system in a cinema generally includes one digital cinema server and two or more digital cinema projectors. The digital cinema server and the digital cinema projectors are connected with signal transmission lines, as shown in FIG. 1. The digital cinema server is used for storing, playing and managing motion picture contents. The projector projects and displays, in form of light, on the screen the broadcast content after receiving it from the server through signal lines. In the projection of stereo movies, two projectors can be used to project left and right eye images respectively, achieving effect of stereo projection by the methods such as polarization.
Since conditions such as architectural characteristics and geometry shapes of auditorium of different cinemas, screen shapes, characteristics of projectors are inconsistent, when the relative positions and angle of projection optic axis and the screen are not sufficiently aligned, it is easy to cause deformation of the pictures for the reasons such as curvature of the screen, if two projectors project identical pictures, a certain degree of ghosting may appear. When projecting a stereo program, relative deformation of the left and right eye images will occur, causing fatigue in viewing.
A stereo digital cinema projection system usually uses a metal screen with high gain, in order to maintain the polarization of light and increase the brightness. When the projected pictures are shown on the metal screen with high gain, since reflection of non-diffuse-reflectance material has certain directionality, unevenness of brightness and color will occur.
In addition, because two or more projection systems have performance differences, there is inconsistency of image appearances such as color and brightness between two or more pictures. In the projection of stereo pictures, this inconsistency will result in degradation of projection quality, also causing the fatigue in viewing. Moreover, measurements such as contrast and sharpness between the pictures projected by a common projection system and a movie source are exactly the same, without mechanism to further improve the picture quality.
In summary, in the projection system of the prior art, for the reasons such as relative positions and angle of the projection optical axis and specific screen characteristics, curvature of the screen and its own non-diffuse-reflection characteristic, and the performance differences between different projectors, the picture quality of images projected by the projection system of the prior art is not high, so the projection system of the prior art has a problem of not guaranteeing the quality of the projected images.